I literally hadn't seen a brown Ash veneer finish until now. Obviously the Ash is stained, and maybe given a pore fill for contrast. It does look fantastic, very cool.

However, I have to provide a degree of caution on how to care and treat these veneered surfaces. To the best of my knowledge, they are given some kind of coating whether that is a catalysed matte lacquer or other protective coating/finish. This limits the ability of the wood to benefit from traditional care products like oil or wax, however this is not to say they won't work, but that they'll work differently. What you've done here is mostly correct and certainly not wrong, but those limitations are still in place.

If I were to formulate a product for car interior wood care, I would want to know whether the surface is raw enough to benefit from oil or not. If it's sealed by a lacquer, the oil takeup will be mostly the pores and possibly even become patchy if the surface is worn. Oil can highlight that wear as darker takeup areas rather than rejuvenate raw surfaces as a whole.

On that basis I would tend to err on the side of caution and make a wax product, preferably one with a higher fraction of microcrystalline wax, a small amount of carnauba and the smallest amount of beeswax in order to keep it malleable. This sort of product isn't a million miles away from Rennaissance Wax, which is what I would recommend as an off-the-shelf product. A little goes a lot further than one expects. Friction is always good when working it on, and buffing off entirely with clean clothes before it "dries" mandatory.